Autonomous ground surface treatment system and method of operation of such a system

ABSTRACT

An autonomous ground maintenance system comprising a vehicle comprising a chassis supported upon a ground surface by ground support members, a container supported by the chassis, the container defining a discharge outlet operable to disperse treating material held within the container to a target area of the ground surface, a gate adapted to selectively open and close the discharge outlet, a sensor adapted to identify the target area, and an electronic controller supported by the chassis, the controller being in communication with the sensor and the gate. The controller is adapted to position the chassis at a location proximate the target area such that the discharge outlet is capable of delivering the treating material to the target area and energize the gate to open the discharge outlet.

The present application is a 35 U.S.C. § 371 U.S. National Stage ofInternational Application No. PCT/US2019/061962, filed Nov. 18, 2019,which claims priority to and/or the benefit of U.S. Provisional PatentApplication Nos. 62/876,086, filed Jul. 19, 2019; and 62/772,231, filedNov. 28, 2018, all of the above of which are incorporated herein byreference in their respective entireties.

Embodiments of the present disclosure relate to autonomous andsemi-autonomous ground surface treatment systems and methods including,for example, vehicles adapted to autonomously detect ground surface(e.g., turf) damage and, in some embodiments, autonomously repair suchdamage.

BACKGROUND

Turf maintenance involves a wide range of equipment used to promote auniform surface on both natural and synthetic turf. For example, tomaintain quality and appearance, top-dressing equipment is often used toapply particulate to both natural and synthetic turf surfaces, whilegrooming devices (e.g., rakes and blades) are used to level and smooththe particulate once applied.

In practice, before using such equipment and procedures, the damagedturf surfaces may first be identified and flagged for repair. Onceidentified, an operator typically transports the repair equipment to thelocation and then manually performs (or manually operates one or moremachines to perform) the needed repairs. Depending on the location andnumber of the areas that require repair and the degree of damage, suchrepair procedures may be time-consuming.

SUMMARY

Embodiments described herein may provide an autonomous groundmaintenance system including: a vehicle comprising a chassis supportedupon a ground surface by ground support members; a container supportedby the chassis, the container defining a discharge outlet operable todisperse treating material held within the container to a target area ofthe ground surface; a gate adapted to selectively open and close thedischarge outlet; a sensor adapted to identify the target area; and anelectronic controller supported by the chassis. The controller is incommunication with the sensor and the gate, wherein the controller isadapted to: position the chassis at a location proximate the target areasuch that the discharge outlet is capable of delivering the treatingmaterial to the target area; and energize the gate to open the dischargeoutlet.

In another embodiment, an autonomous turf maintenance system is providedincluding: a vehicle comprising a chassis supported upon a turf surfaceby ground support members, wherein one or more of the ground supportmembers comprises a drive member adapted to propel and steer the vehicleover the turf surface; one or more motors adapted to power the drivemember; a sensor adapted to identify a target area of the turf surface;and an electronic controller supported by the chassis, the controller incommunication with the sensor and the one or more motors, wherein thecontroller, via the sensor, is adapted to record a geographic locationof the target area.

In still another embodiment, a method of operating an autonomous turfmaintenance vehicle is provided, the method comprising: establishing awork region in which the vehicle will operate, the work regioncomprising a turf surface; transporting the vehicle to the work region;autonomously operating the vehicle across the work region; controllingoperation of the vehicle with an electronic controller associated withthe vehicle; identifying, within the work region, a target area of theturf surface; and recording a geographic location of the target area.

In yet another embodiment, a method of operating an autonomous turfmaintenance vehicle is provided, the method comprising: establishing awork region in which the vehicle will operate, the work regioncomprising a turf surface; and transporting the vehicle to the workregion. The vehicle includes: a chassis supported upon the turf surfaceby ground support members, wherein one or more of the ground supportmembers comprises a drive member adapted to propel and steer the vehicleover the turf surface; one or more motors adapted to power the drivemember; and a container supported by the chassis, the containercomprising a discharge outlet operable to transfer treating materialheld within the container to a target area of the turf surface; a sensoradapted to identify the target area; and an electronic controllersupported by the chassis, the controller in communication with thesensor and the one or more motors. The method further includes:autonomously propelling the vehicle across the work region; andautonomously identifying, with the sensor, the target area.

The above summary is not intended to describe each embodiment or everyimplementation. Rather, a more complete understanding of illustrativeembodiments will become apparent and appreciated by reference to thefollowing Detailed Description of Exemplary Embodiments and claims inview of the accompanying figures of the drawing.

BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING

Exemplary embodiments will be further described with reference to thefigures of the drawing, wherein:

FIG. 1 is a schematic view of an autonomous ground surface treatmentvehicle, e.g., a turf repair vehicle, in accordance with embodiments ofthe present disclosure;

FIG. 2 is another schematic view of the turf repair vehicle of FIG. 1 ,further illustrating aspects used to identify and treat turf damage;

FIG. 3 illustrates a turf repair vehicle in accordance with anotherembodiment of the present disclosure;

FIG. 4 illustrates a turf repair vehicle in accordance with yet anotherembodiment of the present disclosure;

FIG. 5 illustrates a turf repair vehicle in accordance with stillanother embodiment of the present disclosure;

FIG. 6 illustrates an exemplary turf repair system using any one of thevehicles shown in FIGS. 1-5 ;

FIG. 7 is a diagrammatic view of a base station in accordance withembodiments of the present disclosure, the base station forming part ofthe turf repair system of FIG. 6 ;

FIG. 8 illustrates a ground surface treatment vehicle in accordance withanother embodiment of this disclosure, the vehicle configured as a turfrepair implement towed behind a grounds maintenance vehicle (e.g.,utility vehicle);

FIG. 9 is a rear perspective view of an exemplary transport vehicle fortransporting one or more autonomous ground surface treatment vehicles,the transport vehicle shown with a bed in a transport position;

FIG. 10 is a rear perspective view of the exemplary transport vehicle ofFIG. 9 with the bed shown in deployment position;

FIG. 11 is a side elevation view of the transport vehicle of FIG. 9(e.g., with the bed in the transport position); and

FIG. 12 is a side elevation view of the transport vehicle of FIG. 10(e.g., with the bed in the deployment position).

The figures are rendered primarily for clarity and, as a result, are notnecessarily drawn to scale. Moreover, various structure/components,including but not limited to fasteners, electrical components (wiring,cables, etc.), and the like, may be shown diagrammatically or removedfrom some or all of the views to better illustrate aspects of thedepicted embodiments, or where inclusion of such structure/components isnot necessary to an understanding of the various exemplary embodimentsdescribed herein. The lack of illustration/description of suchstructure/components in a particular figure is, however, not to beinterpreted as limiting the scope of the various embodiments in any way.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description of illustrative embodiments,reference is made to the accompanying figures of the drawing which forma part hereof. It is to be understood that other embodiments, which maynot be described and/or illustrated herein, are certainly contemplated.

All headings provided herein are for the convenience of the reader andshould not be used to limit the meaning of any text that follows theheading, unless so specified. Moreover, unless otherwise indicated, allnumbers expressing quantities, and all terms expressingdirection/orientation (e.g., vertical, horizontal, parallel,perpendicular, etc.) in the specification and claims are to beunderstood as being modified in all instances by the term “about.” Theterm “and/or” (if used) means one or all of the listed elements or acombination of any two or more of the listed elements. Still further,“i.e.” may be used as an abbreviation for the Latin phrase id est andmeans “that is,” while “e.g.” is used as an abbreviation for the Latinphrase exempli gratia and means “for example.”

Embodiments of the present disclosure provide autonomous ground surfacemaintenance vehicles and systems, as well as methods of operating (e.g.,autonomously or semi-autonomously) the same within a work region (areawithin which the vehicle will autonomously operate) to assist withidentifying and/or repairing damaged areas of a ground surface. Forexample, the vehicle may be an autonomous turf repair vehicle adapted todetect or otherwise identify an area of damaged turf (a “target area”)such as a divot or rut on a golf course, and to autonomously deliver tothe target area a treating material. As used herein, the term “treatingmaterial” may include any one, or a combination, of organic andsynthetic turf infill, seed, particulate matter (e.g., sand, soil,granular fertilizer or chemicals), and liquid (e.g., liquid fertilizeror chemicals). In some embodiments, the vehicle may identify and flagtarget areas for subsequent treatment, while in other embodiments, thevehicle may autonomously perform the turf repair operation uponidentification of the target area.

While described herein as a robotic turf evaluation/repair vehicle, sucha configuration is exemplary only as systems and methods describedherein also have application to other operated vehicles including, forexample, vehicles adapted to identify and/or repair artificial fieldsand soil and paved (e.g., concrete, asphalt) surfaces as well.

It is noted that the terms “have,” “includes,” “comprises” andvariations thereof do not have a limiting meaning and are used in theiropen-ended sense to generally mean “including, but not limited to,”where these terms appear in the accompanying description and claims.Further, “a,” “an,” “the,” “at least one,” and “one or more” are usedinterchangeably herein. Moreover, relative terms such as “left,”“right,” “front,” “fore,” “forward,” “rear,” “aft,” “rearward,” “top,”“bottom,” “side,” “upper,” “lower,” “above,” “below,” “horizontal,”“vertical,” and the like may be used herein and, if so, are from theperspective shown in the particular figure, or while the vehicle 100 isin an operating configuration (e.g., while the vehicle 100 is positionedsuch that wheels 106 and 108 rest upon a generally horizontal groundsurface 103 as shown in FIG. 1 ). These terms are used only to simplifythe description, however, and not to limit the interpretation of anyembodiment described.

With reference to the figures of the drawing, wherein like referencenumerals designate like parts and assemblies throughout the severalviews, FIG. 1 illustrates an autonomous ground maintenance vehicle(e.g., a robotic turf repair vehicle 100), which may form part of aground repair system that includes various other components, some ofwhich are described in more detail below (for simplicity of description,the vehicle 100 is illustrated schematically in the figures).

As shown in FIG. 1 , the vehicle 100 may include a frame or chassis 102that carries and/or encloses various components of the vehicle asdescribed below. The vehicle 100 may further include ground supportmembers, e.g., one or more (two) rear wheels 106 and one or more (two)front wheels 108, that support the chassis 102 upon a ground surface(also referred to herein as a grass or turf surface) 103.

The vehicle 100 may include a container 110 (not shown in FIG. 1 but seeFIG. 2 ) supported by the chassis and adapted to hold a volume oftreating material 109. For example, the container may be configured as ahopper adapted to hold a volume of particulate matter as shown. Theparticulate matter may be loose particulate or could be configured as aplurality of packages 107 containing the material 109, or a combinationof both. The packages 107 may be beneficial as they may be more easilytransferred to the container 110 and, as further described below, couldbe sliced open before dispersal to a target area. The container 110 mayalso define or include a discharge outlet 111 operable to disperse,transfer, or otherwise dispense material 109 held within the container110 to a target area 201 of the ground surface 103. The discharge outlet111 may be selectively opened and closed via a gate 126 movable by agate actuator 112.

One or both of the rear wheels 106 may form a drive member adapted topropel and steer the vehicle 100 over the ground surface 103. In someembodiments, the front wheels 108 may freely caster relative to thechassis 102 (e.g., about vertical axes). In such a configuration,vehicle direction may be controlled via differential rotation of the tworear wheels 106 in a manner similar to a conventional zero-turn-radius(ZTR) riding vehicle (note that, while only right wheels 106 and 108 arevisible in FIG. 1 , the vehicle 100 may include corresponding leftwheels 106 and 108). That is to say, a separate motor 104 (which mayeach be in communication with a controller 120 supported by the chassis102) may be provided to separately power each of a left and right rearwheel 106 so that speed and direction of each rear wheel may beindependently controlled. In other embodiments, the drive wheels couldbe powered by a single motor (e.g., through a conventional transmissionor transaxle). In addition or alternatively, the front wheels 108 couldbe actively steerable (e.g., using one or more steer motors 105) toassist with control of vehicle 100 direction, and/or could be driven(i.e., to provide a front-wheel or all-wheel-drive vehicle). In yetother embodiments, all four wheels could be conventionally steerable.Such a configuration may allow generally omni-directional movement ofthe vehicle 100, permitting it to translate in any direction in additionto conventional and/or differentially-driven turning.

While described herein as a four wheeled, rear- or all-wheel drivevehicle, such a configuration is not limiting. For example, the vehiclecould be a tri-wheel configuration, wherein two drive wheels (located atthe front or rear) are used to differentially steer the vehicle, and/orone or more wheels are used to conventionally steer the vehicle.

When the one or more motors 104 are energized, the vehicle 100 may bepropelled and steered over the ground surface 103. That is to say, thecontroller 120 may cause the vehicle 100 to be autonomously propelled ortransported across the work region to a location proximate the targetarea 201 such that the discharge outlet 111 is able to deliver thetreating material 109 to the target area. The controller 120 may thenenergize the gate (the actuator 112) to open the discharge outlet asdescribed below.

The exemplary vehicle 100 may further include a power source, which inone embodiment, is a battery 114 having a lithium-based chemistry (e.g.,lithium-ion). Other embodiments may utilize batteries of otherchemistries, or other power source technologies (e.g., solar power, fuelcell, internal combustion engines) altogether, without departing fromthe scope of this disclosure.

The vehicle 100 may further include one or more sensors adapted toprovide location data. For instance, some embodiments may include apositioning system (e.g., global positioning system (GPS) receiver 116and/or other position system that may provide similar data) adapted toestimate a position of the vehicle 100 and provide such information tothe controller 120. As an example of the latter, one or more of thewheels 106, 108 (e.g., both rear wheels 106) may include encoders 118that provide wheel rotation/speed information that may be used toestimate vehicle position (e.g., based upon an initial start position)within a given work region. Other sensors (e.g., dead reckoning, machinevision, infrared detection, beacon triangulation, radio detection andranging (radar), light detection and ranging (lidar), etc.) now known orlater developed may also be incorporated into the vehicle 100. In stillother embodiments, the vehicle 100 may further include a sensor 115adapted to detect a boundary wire when the latter is used to define aboundary of the work region, or to define a path to the work region.

As shown in FIG. 1 , the vehicle 100 may also include the electroniccontroller 120 adapted to monitor and control various vehicle functions.The exemplary controller 120 may include a processor 122 that receivesvarious inputs and executes one or more computer programs orapplications stored in memory 124. The memory 124 may includecomputer-readable instructions or applications that, when executed,e.g., by the processor 122, cause the controller 120 to perform variouscalculations and/or issue commands. That is to say, the processor 122and memory 124 may together define a computing apparatus operable toprocess input data and generate the desired output to one or morecomponents/devices. For example, the controller may be operativelyconnected to the positioning system such that the processor 122 mayreceive various input data including positional data from the GPSreceiver 116 and/or encoders 118 (or other position data), and generatespeed and steering angle commands to the motor(s) 104 to cause the drivewheels 106 to rotate (at the same or different speeds and in the same ordifferent directions). In other words, the controller 120 may controlthe steering angle and ground speed (the speed and direction) of thevehicle 100, as well as the delivery of treating material 109 as furtherdescribed below.

In view of the above, it will be readily apparent that the functionalityof the controller 120 may be implemented in any manner known to oneskilled in the art. For instance, the memory 124 may include anyvolatile, non-volatile, magnetic, optical, and/or electrical media, suchas a random-access memory (RAM), read-only memory (ROM), non-volatileRAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flashmemory, and/or any other digital media. While shown as both beingincorporated into the controller 120, the memory 124 and the processor122 could be contained in separate modules.

The processor 122 may include any one or more of a microprocessor, acontroller, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field-programmable gate array (FPGA),and/or equivalent discrete or integrated logic circuitry. In someembodiments, the processor 122 may include multiple components, such asany combination of one or more microprocessors, one or more controllers,one or more DSPs, one or more ASICs, and/or one or more FPGAs, as wellas other discrete or integrated logic circuitry. The functionsattributed to the controller 120/processor 122 herein may be embodied assoftware, firmware, hardware, or any combination thereof.

In FIG. 1 (as well as in FIG. 2 ), schematic connections are generallyshown between components such as the controller 120, battery 114,motor(s) 104, a gate actuator 112 (described below), optional boundarywire sensor 115, wireless radio 117 (which may communicate with, forexample, a remote computer 119 such as a mobile device/phone, desktopcomputer, local or “cloud”-based (internet-connected) server), and GPSreceiver 116. This interconnection is exemplary only as the varioussubsystems of the vehicle 100 could be connected in most any manner,e.g., directly to one another, wirelessly, via a bus architecture (e.g.,controller area network (CAN) bus, ethernet, etc.), or any otherconnection configuration that permits data and/or power to pass betweenthe various components of the vehicle.

The exemplary vehicle 100 is shown in FIG. 2 with various structuredescribed above removed to better illustrate aspects of the container110 and material delivery components. As indicated in this view, thecontainer 110 (also referred to herein as the “hopper”) may be supportedby the chassis 102. The hopper 110 is adapted to receive and store thetreating material 109 therein. As stated above, the hopper 110 may holdtreating material 109 in most any configuration including, granular,liquid, and packaged (see, e.g., packages 107) form. To simplify hopperloading, the hopper 110 may include an open top as shown. Once treatingmaterial 109 is placed into the hopper 110, a cover (not shown) mayoptionally be used to close the open top to, for example, keep thehopper contents dry.

The discharge outlet 111 is in communication with the hopper 110 and isadapted to disperse or dispense treating material 109 contained thereinto the target area 201. To control the volume of material 109 that exitsthe hopper 110, the gate 126 may be provided. As used herein, “gate” mayrefer to any device that permits flow of material from the outlet to bestopped and started. For example, the gate could be configured as asimple door that opens and closes under control of the gate actuator112. Typically, the gate 126 would remain closed during vehicletransport, but be opened (fully or partially) during turf repairoperations. As with the other control components of the vehicle 100, thegate 126 (actuator 112) may be in communication with the controller 120such that, based upon other parameters recognized by the controller, thegate may be opened and closed to provide a volume of treating material109 to the target area 201.

While shown in FIG. 2 as a divot (enlarged for illustration purposes),the term “target area” may refer to any turf area (or other surface areain non-turf applications) that is damaged or is otherwise distressed ascompared to surrounding turf. For example, target areas may include, butare not limited to, dead grass, diseased areas, weeds, divots, ruts, andmost any other areas that exhibit conditions that may be conducive todisease (e.g., firing, wilting, necrosis of plant tissue, or otherindications of biotic or abiotic stress).

In general, systems in accordance with embodiments of the presentdisclosure may be able to: detect target areas; characterize the targetarea (e.g., determine its size); optionally dispense an appropriatevolume of treating material into the target area; and optionally smooththe treating material over the target area.

Autonomous identification of target areas may be provided by one or moreground analysis sensors, collectively referred to herein as sensor 128.For example, an image sensor 128-1 may be supported by the chassis(e.g., near a front end of the chassis as shown in FIG. 2 ). While shownas being part of the vehicle 100, the sensor 128-1 may be remote fromthe chassis 102, e.g., associated with another ground-based vehicle 300such as a lawn mower (manually or autonomously operated). Alternatively,the remote sensor 128-1 could be placed at one or more fixed locations,e.g., on poles 302 in and around the work region, or could be attachedto an aerial vehicle 304 such as a drone, satellite, fixed- orrotating-wing aircraft, blimp, etc.

The sensor 128-1, which may be in communication (directly or indirectly)with the controller 120, may use data (e.g., image) analysis to identifytarget areas. For example, the sensor 128-1 may be a camera havingappropriate sensors that capture differences in color, contrast, and/orreflectivity between the target area and the surrounding ground surfaceas it views the work region. That is, as target areas 201 may present asareas of different contrast, color, and/or reflectivity compared tosurrounding turf areas, the sensor 128-1, via image/data analysisroutines (e.g., performed by the controller 120 or by anothercontroller/processor associated with the sensor including algorithmsrunning on remote computers and servers), may be able to identify targetareas and relay corresponding locations to the controller 120.

The sensor 128-1 may be most any spectral (e.g., single- or multi-)reflectance measurement sensor (e.g., a generic digital camera or even adevice capable of taking multiple, single point reflectancemeasurements) adapted to identify or “see” (using data processingtechniques), target areas among otherwise healthy areas of turf. Forexample, a multi-spectral sensor typically includes a multi-channeldetector capable of measuring reflected light across one or more bandsof the electromagnetic spectrum. As each channel of the detector islimited to detecting reflection only within its specific wavelengthband, data (which again may be images or a collection of single pointdata measurements) may be obtained that capture brightness and colorinformation of the work region, wherein target areas (soil and/ordistressed turf) may appear differently. The sensor 128-1 may thusprovide data similar to normalized difference vegetation indexes (NDVI).Once again, once the target areas are identified, their coordinates mayultimately be relayed to the controller 120.

Again, while the example above is described as a multi-spectral sensor,a single spectral band sensor may also be utilized without departingfrom the scope of this disclosure. That is to say, detecting andanalyzing reflectance within a single spectral band may be sufficient toidentify target areas within a turf surface.

In some embodiments, the sensor 128-1 may be a digital camera thatcaptures images within the 400-700 nanometer (nm) wavelength range.Image capture using infrared or near-infrared detection in the 700-1100nm wavelength range may also be incorporated, while even longerwavelengths may be used to provide temperature information. In fact,most any wavelength (or range of wavelengths) from ultraviolet to nearinfrared are contemplated within the scope of this disclosure.Regardless of the specific sensor utilized, embodiments of the presentdisclosure may capture data (e.g., images) and evaluate those data(using data/imaging processing techniques) based on differences (e.g.,color, contrast, reflectivity) to detect target areas. While describedas a single sensor, the sensor 128-1 may utilize more than one detector(“stereo” detection) to, for example, also estimate target areasize/volume.

In still yet other embodiments, the sensor 128-1 may be configured as athermal sensor adapted to detect surface temperatures of the workregion. As bare soil and drought-stressed turf are typically warmer thansurrounding turf due to turf transpiration, thermal sensors may bewell-suited for identifying target areas. Similarly, turf generally hasdifferent acoustic attenuation characteristics as compared to soil.Accordingly, the sensor 128-1 could alternatively be configured as anacoustic sensor. In yet other embodiments, the sensor 128-1 could beconfigured as another electromagnetic sensor such as a radio detectionand ranging (radar) device. As turf may present differentelectromagnetic attenuation than soil, radar may also be useful foridentification of target areas.

While the sensor 128-1 is described herein as a non-contacting sensor,other embodiments may identify target areas 201 via mechanicalinteraction with the ground surface 103. For example, as shown in FIG. 2, the vehicle 100 may include a depth sensor 128-2. The depth sensor mayinclude an arm 131 pivotally supported by the chassis 102. A rotatingwheel 132 may be supported at a distal end of the arm as shown, whereinthe wheel 132 rolls across the ground surface 103 during vehiclemovement. As the wheel 132 may follow terrain during operation, it maydrop into a divot or recess (e.g., target area 201) when encountered. Asthe wheel 132 drops, the change in angle of the arm 131 (e.g., relativeto the chassis 102) may be detected by the sensor 128-2 and a signalprovided to the controller 120, wherein the signal corresponds to adepth of the target area 201. The volume of treating material to bemetered to the target area may then be calculated by the controller 120based upon sensed depth. In some embodiments, several wheels 132 andcorresponding arms 131 may be provided transversely across the front ofthe vehicle 100. By providing such multiple sensors 128-2, athree-dimensional map of the target area 201 may be generated. In otherembodiments, depth may be estimated by sensors of other configurations.For example, vertical depth probes or other ground-following devices arecontemplated. Still further, laser scanners may be used to estimatetarget area size and depth.

In addition to sensor-based target area detection, human-generatedreports of target areas 201 may also be used. For example, a golfer (ormaintenance worker) may identify a divot and, via an application runningon a mobile phone or via a text message, send location data of thetarget area to the remote computer 119, which may subsequently providethe location data to the controller 120 of the vehicle 100. In yet otherembodiments, target detection may occur via drone photos or the like.

Once a target area is identified, e.g., via any of the methods andsensors described herein, the geographic location of the target area maybe recorded in the memory 124 of the controller 120 for treatment at alater time and the location wirelessly transmitted to the remotecomputer. Such a configuration may be typical when the detectionfunction is provided by a sensor remote from the vehicle 100 (e.g., whendetection occurs via the vehicle 300, the pole-mounted sensor, or anaerial-based sensor). In other embodiments, data may be transmitted(unidirectionally or bi-directionally) via a wired connection (e.g.,when the vehicle returns to base and docks as described below), or thevehicle may store data on a storage device that may be removed from thevehicle for subsequent data transfer. In still other embodiments, thevehicle 100 may detect the target area 201 and proceed to immediatelytreat it. The latter procedure may be typical when using the onboardsensor 128-1 or 128-2 (which may be collectively and individuallyreferred to as sensor(s) 128). Regardless of whether the treatmentoccurs immediately after identification, the controller 120/sensor 128may be adapted to not only record the coordinates of the identifiedtarget area, but also to wireless transmit data or status informationregarding this and other aspects of the treatment to the remote computer119 (e.g., golf course central computer, cellular phone, internet site,remote server, etc.). The status information may include various data inaddition to the coordinates of the areas treated. For example, dataregarding the volume of treating material used could also be containedwithin the information sent, as well as the date and time material wasdispensed to the target area.

FIG. 2 further illustrates a hopper and material delivery system inaccordance with embodiments of the present disclosure. As statedelsewhere herein, the hopper 110 may be in fluid communication with adischarge chute 113 forming a discharge outlet 111 that may selectivelydirect the treating material 109 contained in the hopper to the targetarea 201. To control the volume of treating material dispersed ordelivered in and around the target area, the gate 126 may be selectivelyopened (moved from a closed position to a fully or partially openposition), under control of the controller 120, via the actuator 112.For example, the gate could be opened for a fixed period of time that iscalculated, based upon various parameters of the treating material andthe chute 113, to adequately fill the target area 201. Once the treatingmaterial is dispersed, the gate 126 may be closed, again under controlof the controller 120.

Accordingly, once the location of the target area 201 is identified(using the sensors described above), the vehicle (e.g., chassis 102) maybe positioned (e.g., autonomously or semi-autonomously) at a locationproximate the target area such that the discharge outlet 111 is capableof delivering the treating material 109 to the target area. That is tosay, the discharge outlet 111 of the container may be positioned, undercontrol of the controller 120, relative to (above) the target area. Insome embodiments, the chute 113 may be fixed, while in other embodimentsthe chute is movable (e.g., rotatable), under control of the controller120, relative to the chassis 102, to permit subsequent repositioning ofthe chute without requiring movement of the vehicle. Such chute movementmay also occur during dispensing of the treating material 109 toaccommodate coverage of larger areas, again without requiring movementof the vehicle 100. While shown herein as a simple chute 113, the outletmay be configured in most any suitable manner, e.g., as one or moreseeder tubes, conveyor belts (see, e.g., FIG. 4 ), etc.

While illustrated as being located beneath the vehicle 100, the chute113 could be configured in a manner similar to a conventionalvehicle-based concrete mixer. That is the chute 113 could be located ona side (front, back, left, right) of the vehicle 100 and may translateor swing to permit distribution of the treating material to a range oflocations proximate the vehicle 100. This again would permit the vehicleto locate proximate the target area, after which the chute may beprecisely positioned over the target area without requiring excessivevehicle movement.

The actuator 112 may form part of a metering system that can bemodulated by the controller 120 to meter (via the gate 126) theappropriate volume of treating material 109 through the outlet 111 tothe target area 201. For example, the system may monitor the volume oftreating material in the hopper 110 in real-time such that the rate andvolume of material released is known by the controller 120. In theembodiment illustrated in FIG. 2 , this monitoring may occur with a loadcell 134 that monitors a weight of the hopper 110. As treating materialis released from the hopper, the load cell may indicate a correspondingreduction in hopper weight, which may be correlated (by known density ofthe material) to a volume of the treating material released.

In other embodiments, the gate 126 could be configured as an auger 136as shown in FIG. 3 , wherein the actuator 112 could be an electricmotor. When the motor is energized, the auger 136 may rotate and delivera known amount of material for each auger rotation. While shown as beingoriented horizontally, the auger 136 could also be oriented vertically,or in most any other orientation, without departing from the scope ofthis disclosure. When the gate is configured as an auger, the term“open” or variations thereof may be used to refer to rotation of theauger, while the term “closed” or variations thereof may be used torefer to non-rotation of the auger.

The auger 136 may be advantageous for some materials and environmentalconditions. For instance, where the treating material 109 particles tendto clump together (e.g., in humid or wet conditions), the auger 136 mayassist in breaking up those clumps before dispensing material to thetarget area 201. The auger 136 may also cause some vibrations that mayassist with drawing the treating material 109 toward the auger. Whilenot illustrated herein, the hopper 110 could include separate vibratingelements that assist in loosening treating material 109 that mayotherwise stick to the walls of the hopper.

FIG. 4 illustrates yet another metering system wherein treating material109 is released again by a mechanical gate 126 similar to the gate shownin FIG. 2 . However, instead of directing the material through a chutedirectly to the target area 201, the gate 126 may time or otherwisemeasure the release of material onto a conveyor belt 138 powered by amotor 139 (similar to some commercial top dressers) in communicationwith the controller 120 (controller not shown in FIG. 4 ). As with thechute 113, the belt 138 may be moved, e.g., pivoted up and down and/orrotated side-to-side, to assist with controlling delivery of thetreating material.

Regardless of the metering system utilized, embodiments of the presentdisclosure may base the metered amount of treating material 109delivered through the discharge outlet to the target area 201 on eitherone or more standardized or fixed volumes (e.g., volumes A, B, C, etc.)of treating material. Alternatively, one or more sensors (e.g.,image/thermal/acoustic sensors 128-1 and/or depth sensor 128-2) may beused to calculate or estimate (with the controller) a required volume tolevel/treat the target area 201 (e.g., deliver a volume of treatingmaterial 109 necessary to completely fill (or slightly overfill) anestimated volume of an identified divot based upon one or moredimensions of the target area). The gate may thus meter the materialbased upon one or both of: time; and a position of the discharge outlet111. In some embodiments, the system may provide a base volume oftreating material (e.g., 240 cubic centimeters (cc)) and may, based uponan estimated volume of the target area, provide a multiple (e.g., 1, 2,or 3 times) of the base volume to treat the area.

The terms “outlet,” “chute,” and “gate” are used herein in a broad senseto indicate most any mechanism that permits controlled transfer oftreating material 109 from the hopper 110 to the target area 201. Forinstance, mechanical arms, blowers, sprayers, conveyors, spinners, andthe like may collectively perform the functions of, and thus operate as,the outlet, chute, and gate without departing from the scope of thisdisclosure.

In alternative embodiments, the vehicle 100 may include a cutter or coretool 350 as shown in FIG. 5 . The tool 350 may be adapted to remove orexcise from the turf surface a predetermined portion of turf around thetarget area (e.g., a clean margin thereabout), leaving a standard sizerecess 351 in the turf surface. A standard volume of treating materialmay then be dispersed to the target area. In some embodiments, insteadof then delivering a volume of granular or liquid treating material 109to the exposed recess 351, the treating material carried in a modifiedhopper 110 may instead be pre-formed “plugs” 352 of sod of acorresponding size that may then be set within the newly-created recess351 in the ground surface 103. In some embodiments, the tool 350 may beadapted to move vertically up and down (directions 357) to permitplacement of the tool relative to the target area 201.

The tool could include two opposing shovel jaws 353 that may, undercontrol of the controller 120 (not shown in FIG. 5 ) be pivoted towardone another as indicated by the arrows 354. One or more motors 355 (alsounder the control of the controller 120) may control both the elevationof the tool 350 as well as the opening and closing of the jaws 353.Accordingly, upon identifying a target area 201, the vehicle may firstexcise the turf surrounding the target area, after which the vehicle maylocate the gate 126 directly over the recess 351. Upon actuation of theactuator 112, the gate 126 may open, allowing the plug 352 to be setwithin the recess 351. The removed material may be stored in a separateonboard hopper (not shown) or ejected to the ground surface 103 where itmay ultimately break down. The vehicle may include cutter tools andplugs of one or more sizes to permit treatment of various target areasizes. As described elsewhere herein, when such plugs are laid, thevehicle may log the location and time/date of repair and relay suchinformation to an irrigation controller to ensure adequate wateringoccurs thereafter.

With reference again to FIG. 2 , the treating material (e.g.,particulate or liquid material) could be placed into the hopper inpackages 107. The packages may form a porous membrane or, when holdingsolids, be water-soluble such that each package, after delivery to thetarget area 201, may breakdown or otherwise release its contents.Alternatively, the hopper 110 may include a slicer 140 or similardevice. The illustrated slicer 140 may rotate (e.g., via a motor (notshown)) during operation, whereby teeth of the slicer are adapted toslice or tear the packages before or during dispersal/delivery to thetarget area. In still other embodiments, the packages may be deliveredintact to the target area, and then ruptured by a reciprocating spike orother tool (not shown) attached to the vehicle 100. The term “slicer”may be used herein to describe any device or process (mechanical orotherwise) adapted to open the packages 107.

After depositing the treating material 109 to the target area 201, thevehicle 100 may distribute or smooth the treating material dispersed inand around the target area using a grooming tool attached or otherwiseconnected to the chassis 102. For example, the vehicle 100 maymanipulate, e.g., tow, a grooming tool 142 (see FIG. 2 ) that includesone or more of a brush, a blade, a squeegee, a drag mat, a roller, arake, an air jet, a water jet, a mechanical abraider (such as that shownin U.S. Pat. No. 10,058,087), and a tamper. The grooming tool 142 may bemanipulated to assist with evenly spreading and smoothing the treatingmaterial 109 dispersed in and around the target area, and to level thetarget area 201 to the same elevation as the surrounding turf. In someembodiments, the vehicle 100 may further include a probe assembly, suchas that described in WO2018/132650, to determine the profile of aninfill material after the material is dispensed to the target area 201and smoothed.

In other embodiments, the grooming tool may be excluded. In thisinstance, subsequently irrigation or movement of other vehicles (e.g.,mower) may eventually distribute the treating material effectively. Inother embodiments, the vehicle 100 may utilize the grooming tool 142 tomitigate interference of debris resulting from damaged or treated turf.For instance, the vehicle may include a sweeper or brush that collectsdebris (aerator cores, divot material, etc.) and stores the debris in anonboard container that may be emptied at a later date using, forexample, a debris sweeper similar to that described in U.S. Pat. No.7,716,773. Alternatively, the debris may be collected and thenpulverized onboard the vehicle utilizing a processor like that describedin U.S. Pat. No. 8,205,681, whereinafter the pulverized debris isdistributed over the ground surface 103.

As stated herein above, after the vehicle 100 has completed dispersingtreating material in and around a target area 201, the time and/or dateof the application, and the coordinates of the treated area, may berecorded (e.g., within the memory of the controller 120 and/ortransmitted to the remote computer 119). Recording the location of thetarget area may be beneficial to avoid unnecessary re-treatment of thesame target area at a later date. Moreover, recording the location mayalso permit onboard or remote sensors 128-1 and 128-2 to monitor theprogress of the treated area over time, and/or to check for washout ofthe infill material at a later date. Still further, recording thelocation of a treated area and transmitting that location to the remotecomputer 119 (see FIG. 6 ) may allow the remote computer to communicatewith an irrigation controller 144 to operate the irrigation zoneencompassing the treated area using a planting irrigation cycle. Aplanting irrigation cycle may deliver less water than a normalirrigation cycle to reduce the opportunity for washout of theinfill/treating material 109, and/or to keep the target area damp tofacilitate seed germination.

FIG. 6 illustrates a portion of an exemplary property 400, e.g., aportion of a golf course. The course may include various turf surfacessuch as fairways, roughs, and teeing areas, the latter of which isillustrated in FIG. 6 as tee area 402. For purposes of this example, theteeing area 402 is a designated work region. However, other sub-areas,or even the entire golf course, could be designated work regions as longas the region includes a turf surface. In fact, due to the confinedspace and ability to visually evaluate the area, tee areas may be moreeasily dealt with using conventional divot repair processes. However,the exemplary processes used to identify, characterize, and treat(disperse and smooth treating material) may be generally the sameregardless of the specific area being treated.

The course may include an equipment or utility building 404, which mayhouse various turf care equipment and course management systems. Forexample, the building may house the remote computer 119 that controlsvarious course systems including an irrigation system controlled by anirrigation controller 144. While shown as being housed in a buildingadjacent to the course, the remote computer could be located at most anyremote site as long as such remote site is able to communicate with thevarious course management systems (e.g., via the internet).

The vehicle 100 may be stored at a base station 406. The base stationmay permit not only storage and re-charging of the vehicle's battery(see battery 114 in FIG. 1 ), but also store and replenish the treatingmaterial 109 as further described below.

After establishing the work region, the vehicle may be dispatched orotherwise transported to the work region 402 to conduct regular turfevaluations (using onboard sensors 128-1, 128-2). In addition oralternatively, the vehicle 100 may be dispatched after receivingcoordinates of target areas from remote sensors (e.g., associated withaerial vehicles 304, other ground vehicles 300, or fixed locations(e.g., sensors attached to posts 302 located in and around the workregion 402)) or from reports from golfers or maintenance personnel.

The vehicle 100 may move from the base station 406 to the work region402 either autonomously or via operator-assisted propulsion. Again,while the work region 402 is defined in this example as a golf courseteeing area, the work region could be most any portion of the course(e.g., tee, fairway, rough, or green). Moreover, most any method may beused to establish the work region. For example, the work region could beestablished by providing the controller 120 with a geographic locationof the boundary of the work region by, for example: pre-programming ofthe boundary; learning the boundary during a training phase; receivinginformation from another vehicle (e.g., vehicles 300 and 304; see FIG. 2); receiving boundary information from a beacon 308 (e.g., attached toposts 302) or the like); receiving boundary information from the remotecomputer 119; identifying player stopping locations; and receivinginformation from player reports (e.g., via text messages or a mobilephone application).

Once within the work region 402, the vehicle 100 may operateautonomously across the work region under control of the controller 120to either: move directly to a known target area 201 location; or beginsearching for target areas by moving in a planned, random, orsemi-random pattern. For example, the vehicle could move to an initiallocation (e.g., geometric center) of the work region and then moveoutwardly in a spiral pattern (see dashed lines in FIG. 6 ) until theentire work region is covered. In this sense, the work region could beviewed as an electronic “tether” defining a radius from a startingpoint. In such an embodiment, the “center” of the work region could bedefined by a beacon (permanent or temporary), or could otherwise beknown by its coordinates.

Once the target areas are identified and treated as described above, thevehicle 100 may be transported back to the base station 406. Again,transport may occur under either autonomous, semi-autonomous, oroperator-assisted control.

FIG. 7 schematically illustrates a base station 406 in accordance withembodiments of the present disclosure. For autonomous return to the basestation, the vehicle 100 may transport back to known coordinates andthen use a beacon on the base station or machine vision techniques todock with the base station as shown in FIG. 7 .

The base station may include a frame 408 near which the vehicle 100 mayposition itself when docked. The frame may also have connected thereto apower connection 410 and optionally a wired or wireless data connection412. The power connection 410 may deliver electrical power to contacts414. The vehicle 100 may include corresponding contacts such that, whenthe vehicle 100 is docked, the battery 114 (see FIG. 1 ) may berecharged via the power connection. The data connection 412 mayoptionally be provided to allow remote access to the memory 124 of thecontroller 120, and to provide status of the vehicle 100 and basestation 406, e.g., to the remote computer 119.

In some embodiments, the frame 408 of the base station 406 may support amaterial hopper 416 having an option lid 417 as shown. The materialhopper 416 may contain a volume of treating material 109 that may beused to replenish the hopper 110 of the vehicle 100. To control transferof treating material 109 from the material hopper 416, a gate 418 andgate actuator 420 may be provided and operated similar to the gate 126and actuator 112, respectively, described above. That is to say, thecontroller 120 and/or remote computer 119 may energize the actuator 420to open the gate 418 once the vehicle 100 is docked.

In order to automatically ensure the appropriate volume of treatingmaterial 109 is transferred from the material hopper 416 to the vehiclehopper 110, various sensors may be used. For example, the load cell 134(see FIG. 2 ) may continuously indicate to the controller 120 and/ordirectly to the remote computer 119 (e.g., via the data connection 412)the volume of treating material in the hopper 110. Once the load cellprovides a signal corresponding to the presence of the desired volume oftreating material 109, the gate 418 may be closed. In other embodiments,other sensors (e.g., cameras, flow-based sensors) may be used to detectthe volume of material transferred to the hopper 110, while in stillother embodiments, hopper 110 replenishment may be accomplishedmanually.

While described herein above as a self-contained, autonomously orsemi-autonomously guided vehicle 100, other configurations are certainlypossible. For instance, FIG. 8 diagrammatically illustrates anautonomous ground maintenance system having a towed implement 500 pulledbehind an operator-controlled maintenance vehicle such as a maintenancevehicle or tractor 502. In such a configuration, the tractor 502 maytransport the implement 500 over the turf surface 103, negating the needfor autonomous self-propulsion of the implement 500. However, theimplement 500 may be similar in most other respects to embodiments ofthe vehicle 100 described herein. For example, the implement 500 mayinclude sensors 128-1, 128-2 (onboard or remote) to identify targetareas 201, and may further include a hopper 510 and gate 526, the gatebeing autonomously controlled (by the controller 120) to autonomouslydistribute treating material 109 from the hopper 510 to identifiedtarget areas 201 in a manner already described herein. Such a towedconfiguration (with autonomous treatment capabilities) may providevarious benefits including, for example: elimination or simplificationof some or all of the autonomous navigation and propulsion systems;accommodation of a greater volume of treating material (and/orpermitting refilling of treating material from a hopper (not shown) onthe tractor 502 via one or more dispensing outlets); and the ability topull a heavier grooming tool 142.

Systems and methods in accordance with embodiments of the presentdisclosure may further utilize a transport vehicle that may carry one ormore (e.g., a plurality) of the vehicles 100 onboard and deliver andretrieve the vehicles 100 from various (e.g., first and second) workregions. For instance, FIGS. 9-12 illustrate a transport vehicle 600that includes provisions for carrying one or more (e.g., a plurality of)vehicles 100 (vehicles 100 not shown in these views). While shown as ariding vehicle 600, other embodiments may provide a remote-controlled orautonomously-controlled vehicle.

In some embodiments, the transport vehicle 600 may be a modified versionof the model Workman HD utility vehicle sold by The Toro Company ofMinneapolis, Minn. USA. The vehicle 600 may include an operator station602 to accommodate a sitting operator (and, optionally, one or morepassengers). The operator station 602 may include one or more controls(e.g., steering wheel, speed control, brake control, etc.) that permitthe operator to control movement and operation of the vehicle 600 overthe ground surface 103. The vehicle 600 may be supported upon the groundsurface by wheels, 606, 608 (only left side wheels visible, with rightside wheels being generally mirror-images of their left sidecounterparts). One or more of the wheels (e.g., rear wheels 606) may bepowered to propel the vehicle during operation, while the same or otherwheels (e.g., front wheels 608) may be conventionally steerable (othersteering geometries, e.g., differentially driven drive wheels, are alsocontemplated). The vehicle 600 may include a prime mover 604 (e.g.,internal combustion engine or energy storage device (e.g., battery) asshown in FIG. 10) to power not only the drive wheels but other systemsassociated with the vehicle 600.

As shown in FIGS. 9 and 10 , the vehicle may also include a bed 610defining a space 612 operable to receive and support therein one or moreof the vehicles 100. The bed 610 may, in some embodiments, be movablebetween a transport position as shown in FIGS. 9 and 11 , and adeployment position as shown in FIGS. 10 and 12 . In the transportposition, the vehicle 600 may be suited to transporting the carriedvehicle(s) 100 between multiple locations. Upon reaching a desiredvehicle deployment location, however, the bed 610 may be placed in thedeployment position, wherein vehicle(s) 100 carried thereon may exit thebed and begin autonomous operation as described elsewhere herein. Thebed 610 may include a ramp 614 (either fixed or movable to a rampposition) that assists with vehicle 100 deployment.

While not wishing to be bound to any particular embodiment, FIGS. 11-12(various vehicle 600 structure removed in these views for clarity)illustrate an exemplary bed movement system 616 adapted to move the bed610 from the transport position (FIG. 11 ) to the deployment position(FIG. 12 ). In this embodiment, each side of the bed 610 is connected toa frame 602 of the vehicle 600 by two links to form a four-bar linkage618 (only left side linkage is shown, but right side is a mirror image).Each side further includes an operator-controlled hydraulic cylinder 620having a cylinder end connected to the frame 602 and a rod end connectedto a forward link 622 of the four-bar linkage 618.

The forward link 622 may be configured in a dog-leg shape that pivotallyattaches to the frame 602 at a frame pivot 623 and to the bed 610 at abed pivot 624. Each four-bar linkage 618 further includes a rear link626 pivotally connected to the frame 602 at a frame pivot 627 and to thebed 610 at a bed pivot 628. As each of the cylinders 620 retract fromthe position shown in FIG. 11 to the position shown in FIG. 12 , the bedmay move through an arc 630 defined by the links 622 and 626. The linksare designed to maintain the floor of the bed level throughout its rangeof motion. Moreover, the links 622, 626 are designed to travel overcenter when returning to the position shown in FIG. 11 . As a result,positional placement of the bed in the transport position is notdependent upon maintaining hydraulic pressure to the cylinders 620.

In operation, the transport vehicle 600 may be propelled (e.g.,autonomously, semi-autonomously, or under direct or remote operatorcontrol) to haul vehicle(s) 100 among one or more work regions. Forexample, the transport vehicle may be propelled from a first location toa second location, wherein the second location is in or proximate afirst work region. Upon reaching the second location, the transportvehicle 600 may deliver one or more of the vehicles 100 from the bed 610to the first work region, after which the vehicle 100 may operate, e.g.,autonomously, as described herein. The transport vehicle may then moveto other work regions and deploy other vehicles 100.

When a particular vehicle 100 has completed coverage of a work region(e.g., the first work region) or requires replenishment of its treatingmaterial hopper 110, it may communicate status information to (an/orreceive status information from) the transport vehicle 600 (e.g., usinga radio 640 on the vehicle 600 as shown only in FIG. 10 ). Such statusinformation may include, but not be limited to, requesting: pick up; tohave its treating material hopper 110 refilled with treating material109 from a hopper 650 (see also FIG. 10 ) located on the transportvehicle; and/or to have its battery recharged or replaced via facilitiesalso provided on the vehicle 600.

Once the vehicle 100 has completed its work, the transport vehicle 600may retrieve and then re-deploy the vehicle 100 to another work regionor return the vehicle(s) to a home or base location.

While described herein as autonomously detecting and treating targetareas, other embodiments may allow an operator to manually distributetreating material via remote control. In such a configuration, targetareas could be observed directly by the operator, or could be remotelyobserved using cameras located upon the vehicle 100.

Various illustrative embodiments are within the scope of thisdisclosure, some examples of which are identified below.

Embodiment 1. An autonomous ground maintenance system comprising: avehicle comprising a chassis supported upon a ground surface by groundsupport members; a container supported by the chassis, the containerdefining a discharge outlet operable to disperse treating material heldwithin the container to a target area of the ground surface; a gateadapted to selectively open and close the discharge outlet; a sensoradapted to identify the target area; and an electronic controllersupported by the chassis, the controller in communication with thesensor and the gate.

Embodiment 2. The system according to Embodiment 1, wherein thecontroller is adapted to: position the chassis at a location proximatethe target area such that the discharge outlet is capable of deliveringthe treating material to the target area; and energize the gate to openthe discharge outlet.

Embodiment 3. The system according to any one of Embodiments 1-2,further comprising a grooming tool connected to the chassis and adaptedto distribute the treating material in and around the target area.

Embodiment 4. The system according to any one of Embodiments 1-3,wherein the sensor comprises an image sensor adapted to identify adifference in contrast, color, or reflectivity between the target areaand the surrounding ground surface.

Embodiment 5. The system according to any one of Embodiments 1-3,wherein the sensor comprises a depth sensor.

Embodiment 6. The system according to any one of Embodiments 1-3,wherein the sensor comprises either a thermal sensor or an acousticsensor.

Embodiment 7. The system according to any one of Embodiments 1-3,wherein the sensor comprises a radio detection and ranging device.

Embodiment 8. The system according to any one of Embodiments 1-3,wherein the sensor comprises a spectral reflectance measurement sensor.

Embodiment 9. The system according to any one of Embodiments 1-8,wherein the discharge outlet is movable, relative to the chassis, undercontrol of the controller.

Embodiment 10. The system according to any one of Embodiments 1-9,wherein the sensor is remote from the chassis.

Embodiment 11. The system according to any one of Embodiments 1-10,wherein the treating material comprises at least one of infill, seed,particulate matter, and liquid.

Embodiment 12. The system according to any one of Embodiments 1-11,wherein the treating material is contained in a plurality of packages.

Embodiment 13. The system according to Embodiment 12, wherein the systemfurther comprises a slicer adapted to slice the packages before orduring dispersal of the treating material to the target area.

Embodiment 14. A method of operating an autonomous turf maintenancevehicle, the method comprising: establishing a work region in which thevehicle will operate, the work region comprising a turf surface; andtransporting the vehicle to the work region. The vehicle comprises: achassis supported upon the turf surface by ground support members,wherein one or more of the ground support members comprises a drivemember adapted to propel and steer the vehicle over the turf surface;one or more motors adapted to power the drive member; a containersupported by the chassis, the container comprising a discharge outletoperable to transfer treating material held within the container to atarget area of the turf surface; a sensor adapted to identify the targetarea; and an electronic controller supported by the chassis, thecontroller in communication with the sensor and the one or more motors.The method further includes: autonomously propelling the vehicle acrossthe work region; and autonomously identifying, with the sensor, thetarget area.

Embodiment 15. The method according to Embodiment 14, further comprisingrecording a location of the target area within a memory of thecontroller.

Embodiment 16. The method according to any one of Embodiments 14-15,further comprising transmitting data regarding a location of the targetarea to a remote computer.

Embodiment 17. The method according to any one of Embodiments 14-16,further comprising: positioning, under control of the controller, thedischarge outlet of the container relative to the target area;selectively opening, under control of the controller, a gate associatedwith the discharge outlet to disperse the treating material in andaround the target area; and closing, under control of the controller,the gate.

Embodiment 18. The method according to any one of Embodiments 14-17,wherein the vehicle further comprises a grooming tool, and wherein themethod further comprises manipulating the grooming tool with the vehicleto smooth the treating material dispersed in and around the target area.

Embodiment 19. The method according to Embodiment 18, wherein thegrooming tool comprises a tool selected from a brush, a blade, asqueegee, a drag mat, a roller, a rake, an air jet, a water jet, amechanical abrader, and a tamper.

Embodiment 20. The method according to any one of Embodiments 14-19,further comprising recording a time and date at which the treatingmaterial was dispersed in and around the target area.

Embodiment 21. The method according to any one of Embodiments 14-20,further comprising metering the treating material dispersed through thedischarge outlet.

Embodiment 22. The method according to Embodiment 21, wherein meteringthe treating material dispersed through the discharge outlet comprisesmetering the treating material based upon one or both of: time; and aposition of the discharge outlet.

Embodiment 23. The method according to Embodiment 21, wherein meteringthe treating material through the discharge outlet comprises metering afixed volume of the treating material.

Embodiment 24. The method according to Embodiment 21, wherein meteringthe treating material through the discharge outlet comprises metering avolume of treating material, the volume estimated by the controller tofill the target area based upon a dimension of the target area.

Embodiment 25. The method according to Embodiment 21, further comprisingmeasuring a depth of the target area with a depth sensor andcalculating, with the controller, a volume of treating material to bemetered to the target area.

Embodiment 26. The method according to any one of Embodiments 14-25,further comprising removing from the turf surface a predeterminedportion of turf around the target area before dispersing the treatingmaterial in and around the target area.

Embodiment 27. The method according to any one of Embodiments 14-26,wherein transporting the vehicle to the work region comprises: providinga transport vehicle comprising a bed, the bed adapted to received andsupport a plurality of the turf maintenance vehicles; propelling thetransport vehicle from a first location to a second location, the secondlocation being in or proximate a first work region; and delivering afirst turf maintenance vehicle from the bed to the first work region.

Embodiment 28. The method according to Embodiment 27, furthercomprising: returning the transport vehicle to a location at or near thefirst work region; and returning the first turf maintenance vehicle fromthe first work region to the bed of the transport vehicle.

Embodiment 29. The method according to Embodiment 28, comprising:propelling the transport vehicle to a third location; and delivering thefirst turf maintenance vehicle from the bed to a second work region.

Embodiment 30. The method according to any one of Embodiments 27-29,further comprising replenishing the container of the first turfmaintenance vehicle with additional treating material stored on thetransport vehicle.

Embodiment 31. The method according any one of Embodiments 27-30,further comprising communicating status information between the firstturf maintenance vehicle and the transport vehicle.

The complete disclosure of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. In the event thatany inconsistency exists between the disclosure of the presentapplication and the disclosure(s) of any document incorporated herein byreference, the disclosure of the present application shall govern.

Illustrative embodiments are described and reference has been made topossible variations of the same. These and other variations,combinations, and modifications will be apparent to those skilled in theart, and it should be understood that the claims are not limited to theillustrative embodiments set forth herein.

What is claimed is:
 1. An autonomous ground maintenance systemcomprising: a vehicle comprising a chassis supported upon a groundsurface by ground support members; a container supported by the chassis,the container defining a discharge outlet operable to disperse treatingmaterial held within the container to a target area of the groundsurface; a gate adapted to selectively open and close the dischargeoutlet; a sensor adapted to identify the target area, wherein the targetarea comprises natural turf; and an electronic controller supported bythe chassis, the controller in communication with the sensor and thegate, wherein the controller is adapted to: position the chassis at alocation proximate the target area such that the discharge outlet iscapable of delivering the treating material to the target area; andenergize the gate to open the discharge outlet.
 2. The system accordingto claim 1, further comprising a grooming tool connected to the chassisand adapted to distribute the treating material in and around the targetarea.
 3. The system according to claim 1, wherein the sensor comprisesan image sensor adapted to identify a difference in contrast, color, orreflectivity between the target area and the surrounding ground surface.4. The system according to claim 1, wherein the sensor comprises a depthsensor.
 5. The system according to claim 1, wherein the sensor compriseseither a thermal sensor or an acoustic sensor.
 6. The system accordingto claim 1, wherein the sensor comprises a radio detection and rangingdevice.
 7. The system according to claim 1, wherein the sensor comprisesa spectral reflectance measurement sensor.
 8. The system according toclaim 1, wherein the treating material comprises any one, or acombination, of soil, granular fertilizer, or liquid fertilizer.
 9. Amethod of operating an autonomous turf maintenance vehicle, the methodcomprising: establishing a work region in which the vehicle willoperate, the work region comprising a turf surface; transporting thevehicle to the work region, the vehicle comprising: a chassis supportedupon the turf surface by ground support members, wherein one or more ofthe ground support members comprises a drive member adapted to propeland steer the vehicle over the turf surface; one or more motors adaptedto power the drive member; a container supported by the chassis, thecontainer comprising a discharge outlet operable to transfer treatingmaterial held within the container to a target area of the turf surface;a sensor adapted to identify the target area, wherein the target areacomprises natural turf; and an electronic controller supported by thechassis, the controller in communication with the sensor and the one ormore motors; autonomously propelling the vehicle across the work region;and autonomously identifying, with the sensor, the target area.
 10. Themethod according to claim 9, further comprising recording a location ofthe target area within a memory of the controller.
 11. The methodaccording to claim 9, further comprising transmitting data regarding alocation of the target area to a remote computer.
 12. The methodaccording to claim 9, further comprising: positioning, under control ofthe controller, the discharge outlet of the container relative to thetarget area; selectively opening, under control of the controller, agate associated with the discharge outlet to disperse the treatingmaterial in and around the target area; and closing, under control ofthe controller, the gate.
 13. The method according to claim 12, whereinthe vehicle further comprises a grooming tool, and wherein the methodfurther comprises manipulating the grooming tool with the vehicle tosmooth the treating material dispersed in and around the target area.14. The method according to claim 12, further comprising recording atime and date at which the treating material was dispersed in and aroundthe target area.
 15. The method according to claim 12, furthercomprising metering the treating material dispersed through thedischarge outlet.
 16. The method according to claim 15, wherein meteringthe treating material dispersed through the discharge outlet comprisesmetering the treating material based upon one or both of: time; and aposition of the discharge outlet.
 17. The method according to claim 15,further comprising measuring a depth of the target area with a depthsensor and calculating, with the controller, a volume of treatingmaterial to be metered to the target area.
 18. The method according toclaim 9, wherein transporting the vehicle to the work region comprises:providing a transport vehicle comprising a bed, the bed adapted toreceive and support a plurality of the turf maintenance vehicles;propelling the transport vehicle from a first location to a secondlocation, the second location being in or proximate a first work region;and delivering a first turf maintenance vehicle from the bed to thefirst work region.
 19. The method according to claim 18, furthercomprising: returning the transport vehicle to a location at or near thefirst work region; and returning the first turf maintenance vehicle fromthe first work region to the bed of the transport vehicle.
 20. Themethod according to claim 19, comprising: propelling the transportvehicle to a third location; and delivering the first turf maintenancevehicle from the bed to a second work region.